Experimental Hypersensitivity Pneumonitis: Location of Transferring Cells

Cultured cells from Micropolyspora faeni-sensitized donors can adoptively transfer murine experimental hypersensitivity pneumonitis (EHP). We sought to determine the location of transferred cells in recipient animals, the influence of the origin of the cultured cells, and the effect of specific intratracheal challenge. We labeled cultured sensitized spleen or lung-associated lymph node (LALN) cells with CFDA-SE, a cytoplasmic stain, before transfer to naive recipients, which were sacrificed 1 h, 1 day, or 4 days thereafter. We also transferred labeled cultured spleen cells to recipients that were challenged with intratracheal M. faeni and sacrificed 4 days later (MF). Controls were recipients of M. faeni-sensitized and cultured cells challenged with intratracheal normal saline (NS) and recipients of ovalbumin (OVA)-sensitized cells cultured with M. faeni and challenged with intratracheal M. faeni (OVA). The number and proportion of cells that were stained were determined in dispersed spleen, peripheral and lung-associated lymph nodes, and lung parenchyma. The extent of the pulmonary inflammatory response was measured by determining the proportion of microscopic fields that were abnormal and the total number of dispersed pulmonary cells. CFDA-SE stained cells uniformly, and stained cells could be detected in recipients for up to 7 days after transfer. CFDA-SE treatment (0.5 μM) did not affect the ability of cells to transfer EHP adoptively. Transferred cells could be detected easily in lung, lung-associated and peripheral lymph nodes, blood, and spleen. Transferred cells localized to the lung at 1 h but then rapidly decreased with no difference between labeled cells from spleen and LALN. After intratracheal M. faeni challenge, there was no difference in the proportion of labeled cells in the lung among any of the groups (MF, NS, or OVA). There was an increase in the number of lung cells in the MF group compared with the control (NS and OVA) groups. We conclude that cells capable of transfer are transiently (1 h) trapped in the lung but are much decreased in the lung by four days after transfer. After intratracheal antigen challenge of recipients, there is a substantial increase in the number of pulmonary cells in animals exhibiting adoptive EHP but not in the control groups. Transferred cells responsible for EHP are increased in the lungs of animals with adoptive EHP. Accepted for publication: 30 June 1997